1. Field of the Invention
The present invention is directed to a method for enhancing absorption of a medicament that is suitable for transmucosal administration, particularly to a method for enhancing absorption of a medicament suitable for sublingual administration.
2. Description of the Related Art
Transmucosal drug delivery system has been studied for years because it can avoid the liver first-pass effect. The study on this field focuses on how to enhance absorption of the drug. General approaches reported to enhance absorption include the use of various permeation enhancers such as bile salts, surfactants, organic solvents, chelating agents as well as salicylate and Azone®.
Factors affecting the permeation of a drug via oral mucosa, such as sublingual mucosa, include solubility of the drug, partition coefficient, degree of ionization of the drug, and molecular size and weight of the drug. For a given drug, the molecular size and weight are fixed and cannot be changed. Changes in solubility and degree of ionization will influence partition coefficient and permeability. Therefore, optimization of combined solubility and ionization are variable factors to achieving maximum rate and extent of absorption through oral mucosa such as sublingual mucosa.